1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method.
2. Description of the Related Art
In the production of television programs or the like, the imaging, editing, sending, and the like for programs have been increasingly digitized. With the trend toward higher image quality and lower prices of digital equipment due to the advancing digitization technology, the digitization is accelerating also in the field of film making or the like. For instance, video cameras for obtaining the image signals of target images are replacing the film cameras for recording photographed images on films.
When using a film camera, the amount of received light of an object is measured by an illuminometer to adjust exposure. This is necessary to accomplish effective presentment, and also because the luminance level of the image on a viewfinder of the film camera is different from the luminance level of the image recorded on a film. When a video camera is used, the dynamic range of the video camera is narrower than that of a film camera, and a difference in the amount of received light of an object exerts considerable influences. For these reasons, efforts are made to accurately control the amount of received light of an object by using an illuminometer.
In a video camera, a target image is displayed on the screen of an electronic viewfinder formed of a cathode ray tube or the like. The electronic viewfinder allows the luminance and contrast of a displayed image to be adjusted. For each imaging or for each video camera, adjustment is performed using, for example, a waveform monitor, to obtain constant luminance and/or contrast of display images.
Therefore, if imaging is carried out for an extended period of time or many video cameras are used for imaging, then more time and efforts and more equipment for making adjustment are required.
Furthermore, in the case of outdoor shooting, the amount of received light of an object changes with a change in weather or with the elapse of time. In order to obtain desired images, therefore, the amounts of received light must be frequently measured at multiple points to perform primarily the adjustment of the iris of a video camera on the basis of measurement results, thus interfering with efficient shooting.